The present invention relates in general to apparatus for transporting sheets seriatim along a travel path and, more particularly, to an articulated vacuum transport apparatus.
In typical commercial electrostatographic reproduction apparatus (copier/duplicators, printers, or the like), a latent image charge pattern is formed on a uniformly charged dielectric member. Pigmented marking particles are attracted to the latent image charge pattern to develop such image on the dielectric member. A receiver member (for example, a cut sheet of plain bond paper) is then brought into contact with the dielectric member. An electric field, such as provided by an electrically biased roller, is applied so as to effect transfer of the marking particle developed image to the receiver member from the dielectric member. After transfer, the receiver member bearing the transferred image is separated from the dielectric member and transported away from the dielectric member to a fuser assembly at a downstream location. There the image is fixed to the receiver member by heat and/or pressure from the fuser assembly to form a permanent reproduction thereon.
It has been found that electrostatographic reproduction apparatus of the above described type at times exhibit a defect observable in image quality where the image over the trail edge of the receiver member is smeared. It has been determined that this particular image defect occurs, at least in part, when the lead edge of the receiver member enters the fuser assembly with the trail edge still in transfer association with the dielectric member. One reason for the cause of this defect is believed to be that transport disturbances induced by the fuser assembly are transmitted through the receiver member to the receiver member-dielectric member interface.
The problem of having the receiver member under simultaneous influence of the fuser assembly and the dielectric member can be readily overcome by insuring that the distance between the fuser assembly and the receiver member-dielectric member interface is greater than the length of the receiver member in the transport direction. However, this distance can become quite long when handling large size receiver members. The extended distance for the travel path complicates the construction of the transport and the associated elements of the reproduction apparatus. This is particularly significant as to the adjustability of the transport with regard to its location relative to the fuser assembly and the receiver member-dielectric member interface. Moreover, such extended distance has the further negative attribute in that it tends to unduly increase the overall dimensions of the reproduction apparatus.